1. Field of the Invention
A three-part gasket system for sealing opposing flanges without compressing the flanges together, and more particularly a loose-piece gasket that maintains a liquid impervious seal through self-generated lateral contact pressure exerted on each of the opposing flanges.
2. Related Art
Gaskets are used in a wide variety of sealing applications. Typically, the gasket is compressed between opposing flanges to perfect a fluid impervious seal. The compression load is usually accomplished by spacing a plurality of bolts or other fastening devices around the gasket. For practical purposes, both the gasket and the opposing flanges must be designed and constructed out of sufficiently sturdy material so as to support the compression loads necessary to perfect the seal. As a result, the flange members tend to be heavily constructed, thereby adding to overall weight and cost.
U.S. Pat. No. 5,687,975 to Inciong, issued Nov. 18, 1997, describes a gasketed sealing assembly whose objective is to minimize the number of clamping bolts needed to establish an adequate compressive load between opposing flanges. While the Inciong '975 patent represents a noteworthy advance in the art, it nevertheless remains dependent upon maintaining some compressive load between the opposing flanges to maintain a fluid tight seal. Thus, the flanges must be constructed of sufficiently sturdy (and heavy) material to withstand the compression loads.
A more recent example of a prior art attempt to reduce the compression load requirements between opposing flanges may be found in U.S. Publication No. 2006/0118073 to Bauer et al., published Jun. 8, 2006. This technique, while effective, may be considered expensive and not suited for all applications. In this design, the gasket feature is molded directly to one of the flange portions. The gasket member is of elastomeric construction with an embedded stabilizing core made of a rigid plastic material that increases lateral contact pressure on the opposing flange.
Accordingly, there exists a need in this field for a stand-alone gasket such as that used in a three-part system comprising the gasket and a pair of opposing flanges which are sealed together against the passage of liquid without compressing the flanges together. The stand-alone nature of the gasket component reduces overall system cost and facilitates low-cost repairs and maintenance. Therefore, a solution is needed that will enable light-weight flange constructions due to the avoidance of compressive loads. The solution must be low-cost, versatile, durable and easily adapted from one application to the next.